The invention described herein may be manufactured and used by or for the Government of the United Statement of America for governmental purposes without the payment of any royalties thereon or therefor.
1.0 Field of the Invention
The present invention relates to a system used to analyze compositions to determine what chemical elements are present therein and, more particularly, to a system that analyzes an air sample and, if undesired chemical vapors are present therein, provides signals to activate alarms.
2.0 Description of the Related Art
The ambient by which one is surrounded is of utmost importance. However, the ambient may suffer from pollution that allows the surrounding atmosphere to be contaminated, especially by man-made waste and vapor pollutants.
The environment by which one is surrounded may also be invaded by more serious pollutants, especially during terrorist situations or during warfare, in particular, biological warfare. Biological warfare involves the use of living organisms (as disease germs) or their toxic products, such as blister and nerve gases, that attack humans, animals, or plants, with the human suffering severe bodily pain.
Systems for measuring samples to determine the contents thereof are known and some of which may employ ion mobility spectrometers (IMSs), such as described in U.S. Pat. Nos. 4,445,038; 5,083,019; 5,300,773; 5,491,337 and 5,587,581, and all of which are herein incorporated by reference. The IMS provides a quantitative measurement of the contents of the molecules being sampled by measuring a time of xe2x80x9cflightxe2x80x9d of the ions of the molecules through a drift region of the IMS which is determined by the ion mobility characteristic of the ions being sampled and which, in turn, provides the identity and the concentration of the composition being measured. The IMS of the prior art serves well its intended purposes, but it is desired that further improvements to the IMS system be provided.
Accordingly, it is desired that means be provided employing ion mobility spectroscopy technology that analyzes the environment to detect the presence of unwanted chemical agent vapors found in pollutants and, more particularly, in biological warfare agents. More particularly, it is desired that an Ion Mobility Spectrometer (IMS) be provided that yields a quick and improved accurate determination of these unwanted chemical agent vapors so that the environment may be quickly purged thereof.
It is a primary object of the present invention to provide a system utilizing an IMS that accurately detects and monitors for the presence of undesired chemical agent vapors in an environment.
It is another object of the present invention to provide a system employing an IMS that quickly, yet accurately, detects and monitors for the presence of undesired chemical vapors in an environment and, upon detection thereof, provides an alarm indication.
Another object of the present invention is to provide a system having at least first and second configurations so that an alarm condition is only generated if there is an agreement between the detection derived separately from the first and second configurations.
In addition, it is an object of the present invention to provide a system employing first and second IMSs to advantageously detect ions having both predominate positive and negative polarities, respectively, so as to simultaneously detect separate gaseous samples having respective positive and negative charge characteristics.
It is another object of the present invention to provide for an instrument that uses ion mobility spectroscopy technology that analyzes molecules of chemical agent vapors by determining the cluster arrangement of the ions making up the chemical vapor agents and conditions the molecules of selected vapors so that these molecules are more easily and accurately detected by an IMS operated to more advantageously detect ions manifesting a positive charge.
Furthermore, it is an object of the present invention to provide for an ion mobility spectrometer (IMS) that generates an electrical signal which is routed to one of circuitry and software for comparing the electrical signal against predetermined signals indicative of unwanted and/or dangerous compositions of gaseous vapors, and if a match exists therebetween, an alarm is generated.
The invention is directed to a system for sampling the ambient of a selected environment for the presence of unwanted, predetermined chemical vapors therein.
The system includes a device for obtaining a sample of the selected environment and structure for conditioning the sample into a vapor containing known molecules. The system also includes a device for receiving the vapor made up of ion clusters that define ions of the molecules. The receiving device can include first and second ion mobility spectrometers with one of the ion mobility spectrometers having arranged therewith a reagent source. Each of the first and second ion mobility spectrometers provides an electrical signal representative of the respectively received defined ions of the molecules, if desired, the system also includes circuitry for comparing each of the representative electrical signals of the first and second ion mobility spectrometers against predetermined signals representative of predetermined chemical vapors and for generating an alarm signal if a match exists therebetween.